What are Binary Prefixs? Why Memory/Storage Capacity Less than Advertise?

Binary prefixes are a way to express large amounts of data in computing. Unlike the standard metric system, which uses powers of 10 (like 1,000 for "kilo"), binary prefixes are based on powers of 2.

In this article, you will learn, what is binary prefixes and Why memory capacity less than advertising in the Hard disk or SSD.

What are Binary Prefixs?

In computers, Binary prefixes are units of measurement of digital information, these units are kilo- (k or K), mega- (M), giga- (G), tera- (T), peta- (P), and exa- (E). These units defined data quantity in a byte form, based on powers of 2. Instead of using a standard multiple of powers of 10 as defined in System Storage Units. Instead of using a standard multiple of powers of 10 as defined in System Storage Units.

These Binary Prefixes are:

• Kibi (Ki) =2¹⁰ =1024 bytes
• Mebi (Mi) =2²⁰ = 1,048,576 bytes
• Gibi (Gi) = 2³⁰ = 1,073,741,824 bytes
• Tebi (Ti) = 2⁴⁰ = 1,099,511,627,776 bytes
• Pebi (Pi) = 2⁵⁰= 1,125,899,906,842,624 bytes
• Exbi (Ei) = 2⁶⁰= 1,152,921,504,606,846,976 bytes

In 1999, the International Electrotechnical Commission (IEC) brought in these binary prefixes to avoid storage calculation confusion in Bytes and Big Numbers and after that, after 10 years, these binary prefixes became ISO 80000-1 certified. Nowadays, In our voice, these binary prefixes are commonly used in daily life, especially when we work with data storage.

Why is Memory/Storage Capacity Less than Advertised?

It is common confusion for newbie Techy, that you know your SSD or Hard Disk has gave 500 GB storage, also you see in the Packaging Box. But, when you connect your SSD to your computer, you see , there is a small percetgae of gap down, it show 490GB.

Basically, this is happen storage counting system. The manufacturer or Vender use Decimnal system which are based on powers of 10. On the other hand, the computer Operating System, us Binary system, base power of 2 to count the data storage.

Here is the Decimal Prefixes;

• Kilo (K): 1 kilo = 10³=1000 bytes
• Mega (M): 1 mega = 10⁶= 1000000 bytes
• Giga (G): 1 giga = 10⁹= 100000000 bytes
• Tera (T): 1 tera = 10¹²= 100000000000 bytes
• Peta (P): 1 peta = 10¹⁵=1000000000000000 bytes
• Exa (E): 1 exa = 10¹⁸ = 1000000000000000000 bytes

For example, a 1 gigabyte (GB) storage device, advertised by a manufacturer (which is 1,000,000,000 bytes), is interpreted by an OS as 1 gigabyte (GiB), which is 1,073,741,824 bytes.

Here is the exaplantion;

Suppose you have bought a 500GB SSD. you see it has 500GB storage capacity written on the packaging.

Manufacturer's Calculation (Decimal) during Advertise:

500 GB = 500 * 1,000,000,000 bytes = 500,000,000,000 bytes

Computer OS Calculation (Binary):

500,000,000,000 bytes/  1,073,741,824= 465.66 GB

Conclusion

In conclusion, Binary prefixes are units of measurement of storage capacity of Hard disk or SSD. The difference between the advertised storage capacity and actual capacity in OS in the computer is due to using binary prefixes and decimal numbers. I hope you have learned the clear concept of it, from this article.